1. Field of the Invention
The present invention relates to a socket or female member of a snap button made of metal fastened to clothing, baggages, etc. and a press tool for fastening the female member to a fabric piece, etc. composing the above-mentioned articles.
2. Description of the Prior Art
A typical snap button female member of the type described is disclosed in Japanese Utility Model Publication No. 4-37450. The disclosed female member comprises a cylindrical body having one end slightly flared to provide a space, an annular spring disposed in the space and a cap having its peripheral edge folded thereon and fastened to the one end of the cylindrical body with the annular spring disposed in the space.
Another snap button female member is disclosed in the U.S. Pat. No. 5,101,541. The female member comprises a cylindrical collet including a central through opening, an annular flange extending radially outwardly from the collet, an annular spring received in the collet and a cylindrical hub having its lower marginal edge flared to form an anchoring lug. The annular flange has a first and second series of ridges formed on its upper surface, the first series of ridges folded over the spring to retain the spring on the collect and the second series of ridges also folded over the the anchoring lug of the cylindrical body to fastening the cylindrical hub to the collet.
The first type of conventional female member has a drawback in that, when the female member is clinched to a fabric piece of clothes or a baggage, clinching forces focus on the joint between the cylindrical body and the cap and are likely to deform the cylindrical body and the cap there, thereby causing a gap between the cylindrical body and the cap. As a result, the cylindrical body and the cap are inclined to turn relative to each other, which is prone to cause unravelling of the edge of the hole to which the female member is attached. Furthermore, if too strong forces are exerted on the cap, the end of cylindrical body is squeezed to cause the spring stuck to the cylindrical body, leading to malfunction of the snap button.
The second type of conventional female member has a drawback in that it is complex in construction and bulky so that it cost much and its manufacture and assemble takes much time.